@johnckealy John, many thanks for your explanation and fingers crossed you will "come up" with a fix.
Didn't want to come across as a pedant but with such a great product this fix would be the "icing on the cake".
It is possible to either close the left pane and keep the lines active, or uninstall the plugin complete. (Few plugins uninstall cleanly.)
Windy style time progress bar added for Full year (desktop and mobile).
Different terminator times, for the picker position, displayed in left pane as the picker is moved.
Click on a time-pair to display this in the picker if you want.
Time zone name, daylight saving time rules and offset displayed.
Terminator lines are responsive to the satellite of radar overlay timestamps.
Previously added (see above): use the URL to open at a location or time like this: